As long as Sewer Pack is on the battlefield, you may cast spells named Sewer Pack from your graveyard. Sewer Pack gets +1/+1 for each other creature on the battlefield named Sewer Pack.
2022-06-01 — Updated "card" wording to "spell" for Adventures and modal DFCs.<Aurora, Soulweaver; Butcher of Shallow Graves; Chew the Scenery; Chigau, the Red Market; Dreamsteel Paladin; Metronome; Rainy Night Lovers; Realms Overturning; Performer of Enlightenment//Sartha, the Living Source; and .>